I. Field of the Invention
The present disclosure relates generally to the fields of chemistry and materials science. More particularly, it concerns metal-organic frameworks, compositions thereof and methods use thereof, including for separating gas molecules, sensing, heterogeneous catalysis, drug delivery, lithium sulfide battery, membrane and analytical devices.
II. Description of Related Art
Microporous metal-organic frameworks (MOFs) have been rapidly emerging as new type of porous materials for gas storage, separation, sensing and heterogeneous catalysis. The tunable pores and the immobilized functional sites within such microporous MOFs have enabled them to direct specific recognition of certain molecules based upon size and functionality.
Precise control of pore sizes and pore surfaces within porous materials is very important for their highly selective recognition and thus separation of small molecules. The pores within such porous MOFs can be systematically modified simply by changing the secondary building blocks (SBUs), changing the organic bridging linkers and controlling the framework interpenetration (Deng et al., 2010; Chen et al., 2010; Ma et al., 2010; Horike et al., 2009). In fact, to systematically tune the micropores to induce their size specific encapsulation of small gas molecules, various series of microporous metal-organic framework materials have been emerging as the promising microporous media for the recognition and separation of small gas molecules (Kitaura et al., 2004; Chen et al., 2004; Cho et al., 2006; Liu et al., 2010; Murray et al., 2010; Ma et al., 2009; McKinlay et al., 2008; Dubbeldam et al., 2008; Chen et al., 2006; Finsy et al., 2008; Bae et al., 2010; Zhang et al., 2008; Dybtsev et al., 2004; Li et al., 2009; Vaidhyanathan et al., 2006; Nuzhdin et al., 2007; Dybtsev et al., 2006; Chen et al., 2008).
When considering the organic linkers, m-benzenedicarboxylate organic linkers in MOF play a crucial role in the realization of highly porous MOFs. In fact, this fundamental organic building unit can be incorporated into a great number of organic linkers with different aromatic backbones, leading to a variety of highly porous MOFs for gas storage and separation. (Chen, et al., 2005; Lin, et al., 2006; Lee, et al., 2008; Hu, et al., 2009; Farha, et al., 2010; Yuan, et al., 2010; Yan, et al., 2010; Li, et al., 2011; Zheng, et al., 2011; Guo, et al., 2011; Liu, et al., 2012; Farha, et al., 2012) Recently, the two porous MOFs with BET surface area over 7000 m2/g have been targeted from two hexacarboxylate organic linkers build from three m-benzenedicarboxylate units in Farha, et al., 2012, which is incorporated herein by reference. The introduction of the multivalent ligand by modifying the connection point of the chelating ligand provides the flexibility to augment the pore size of the MOF through systematic modification of the organic linkers. The systematic modification allows for the selective incorporation of different gas molecules based upon the linkers and the resultant pore size.
Motivated by the power of the m-benzenedicarboxylate organic building unit to construct highly porous MOFs, work has been done to expand the organic units as shown in FIG. 1(a) (middle and right ones), for the design of new organic linkers and thus porous MOFs through their self-assembly with the paddle-wheel Cu2(CO2)4 SBUs. Such expanded organic units have never been utilized before to create porous MOFs.